Viswanathan, V., et al. 2018. Why Aren’t There Electric Airplanes Yet? It Comes Down to Batteries. Batteries need to get lighter and more efficient before we use them to power energy-guzzling airplanes. Smithsonian.

“…for a given weight, jet fuel contains about 14 times more usable energy than a state-of-the-art lithium-ion battery….the best batteries store about 40 times less energy per unit of weight than jet fuel. That makes batteries relatively heavy for aviation. Airline companies are already worried about weight – imposing fees on luggage in part to limit how much planes have to carry.”

So what about a flying car (e-VTOL)?

We looked at how much energy a small battery-powered aircraft of 2,200 pounds (1,000 kilograms, including a passenger) capable of vertical takeoff and landing would need. While actually flying, the air vehicle would need 400 to 500 watt-hours per mile, about what an electric pickup truck would need, which is twice as much energy used as an electric car.

But taking off and landing require a lot more power, at least 8,000 to 10,000 watt-hours per trip, or half the energy in a compact electric car such as the Nissan Leaf.

So for an entire flight of 20 miles you’d need 800 to 900 watt-hours per mile — half as much energy as a fully loaded semi-truck. Using that much energy means these aren’t likely to take off.

“Aircraft designers also need to closely examine the power – or how quickly the stored energy is available. This is important because ramping up to take off in a jet or pushing down against gravity in a helicopter takes much more power than turning the wheels of a car or truck.

Therefore, e-VTOL batteries must be able to discharge at rates roughly 10 times faster than the batteries in electric road vehicles. When batteries discharge more quickly, they get a lot hotter. Road vehicles’ batteries don’t heat up nearly as much while driving, so they can be cooled by the air passing by or with simple coolants. But an e-VTOL would generate an enormous amount of heat on takeoff that would take a long time to cool – and on short trips might not even fully cool down before heating up again on landing.

This huge amount of heat will shorten an e-VTOL batteries’ life, make them more likely to catch fire, and require specialized cooling systems that add additional weight and energy demands on the battery.

Schrope, M. 6 Nov 2010. Fly Electric. New Scientist.

A 200-seat airplane weighs about 115 tons at take off.

About a third, or 38 tons of that weight is the kerosene fuel.

The other 77 tons are the passengers, their luggage, and the airplane itself.

An electric, battery-powered airplane would require nearly 3,000 tons of lithium-ion batteries – the batteries would weigh 39 times more than the plane, passengers, and their luggage.

“makati has so many enemies, including ones he doesn’t know about, it’s unbeleivable.” “He has many friends too.”

Yea, a lunatic JuanP who is playing ever more elaborate games. He is likely the one who posted the “I hate makati” sock shit so he could start his further sock games. It is obviously his words. You guys like playing along with this and you whine about it. It shows how fraudulent the both of you are. It advances your agenda in cheap and dirty ways. Instead of truth and honesty we get cheap and fake.

Davy on Fri, 15th Mar 2019 5:51 am

“Cloggie, the US has too much to lose if the 737 is junk, like most things made in the US these days. Some $600 billion in contracts.”

A lot of places stand to lose makato. This plane is sourced from around the world. The plane is not junk. A fix will be found and it will be back up and running. It appears this is a software problem. It also appears Boeing is negligent for trying to down play problems and avoiding a needed grounding. They will pay for this that is for sure. There are way too many orders for the 737 not to work out. There is no way Airbus or China can produce enough planes to take over form Boeing. Incidents like this allow people like you to come out and say things that don’t add up. You do this all the time and it is all about the US bad and your team good. Extremism at its nastiest is what you are.

Not JuanP said Davy Davy on Thu, 14th Mar 2019 8:51 p
Not JuanP said Mental Health America of Eastern Missouri on Thu,…

Davy on Fri, 15th Mar 2019 6:31 am

OH BOY, Mr. Mental Illness is up to start his mindless games. Let the fun begin. JuanP you are the biggest reason this forum has fallen apart. You and your anti-American friends have failed to remove me so now you are obsessed with taking me down by whatever means including mindless noise. You are playing evermore elaborate games that show just how beaten you are. Every day I am here is a day of defeat for you. BTW, your excuses for doing what you are doing are false. If you go back it is you that has done the attacking and the nasty behavior. You have not made a real comment in months because you have nothing to say. All you are doing is showing your feeling and personality disorder.

“Weather has a major effect on the productivity of wind turbines. Both the Polar Vortex and El Niño have reduced the output of wind turbines in the Midwest. During the polar vortex, wind turbines automatically shut off in the extreme cold because the low temperatures take a toll on various parts of a turbine, from electrical cabinets to the gearbox, the generator, lubricants and steel components, which can become brittle if the temperature drops low enough. Coal and natural gas plants had to ramp up production to meet the shortfall and keep the lights on. Also affecting the productivity of wind turbines is El Niño that brought calm winds to the Midwest, reducing wind output by 14 percent despite having added new turbines to the region. American electricity consumers, who expect their electricity to be available at the touch of a switch, should be very cautious about policies to mandate 100-percent renewable energy sources that are dependent on natural weather events.”

“The Energy Information Administration analyzed the generating technologies used during the polar vortex period, finding that, on January 30, wind accounted for an average of 5 percent, coal supplied about 41 percent, natural gas supplied about 30 percent, and nuclear supplied about 12 to 15 percent of the system operator’s load. During the polar vortex, wind turbines shut off when temperatures dipped below minus 20 degrees Fahrenheit. There has been little focus on developing wind turbines to operate below minus 20 degrees Fahrenheit because at these temperatures, there is not much wind blowing. The economics of producing wind energy in such extreme conditions would not justify the additional cost, according to wind experts.”

“What happens when energy prices are at once too high for consumers to afford, but too low for suppliers to earn a return on capital? That’s the situation now with petroleum, but it’s likely to apply across the gamut of energy supply as economic trends unfold. On the one hand, prosperity has turned down, undermining what consumers can afford to spend on energy. On the other, the real cost of energy – the trend energy cost of energy (ECoE) – continues to rise.”

“Critical pre-conditions Apart from the complete inability of the economy to function without energy, two other, critical considerations point emphatically in this direction. The first is the vast leverage contained in the energy equation. The value of a unit of energy is hugely greater than the price which consumers pay (or ever could pay) to buy it. There is an overriding collective interest in continuing the supply of energy, even if this cannot be done at levels of purchaser prices which make commercial sense for suppliers. The second is that we already live in an age of subsidy. Ever since we decided, in 2008, to save reckless borrowers and reckless lenders from the devastating consequences of their folly, we’ve turned subsidy from anomaly into normality.”

“On this basis, it’s become ‘consensus wisdom’ to assume that renewables will, like the 7th Cavalry, ‘ride to the rescue in the final reel’. Unfortunately, this comforting assumption rests on three fallacies.”
The first is “the fallacy of extrapolation”, which is a natural human tendency to assume that what happens in the future will be an indefinite continuation of the recent past. (One of my mentors in my early years in the City called this “the fallacy of the mathematical dachshund”). The reality is much likelier to be that technical progress in renewables (including batteries) will slow when it starts to collide with the limits imposed by physics.
The second fallacy is that projections for cost reduction ignore the derivative nature of renewables. Building, say, a solar panel, a wind turbine or an electrical distribution system requires inputs currently only available courtesy of the use of fossil fuels. In this specialised sense, solar and wind are not so much ‘primary renewables’ as ‘secondary applications of primary fossil input’.
The third problem is that, even if renewables were able to stabilise ECoE at, say, 8% or so, that would not be anywhere near low enough.”

NathanPhillipsAKAfmr-paultard on Sat, 16th Mar 2019 8:32 pm

when will the eurotard solve some of the engineering issues presented by (((supertard))) alice regarding flying cars powered by electricity?

what about a runway using groudn based electricity or some mechanism to continually charge the plane while it’s airborne?

eurotard is useless. he only write something on his “blog” and disable comments.

he’s all about astroturfing accomplishments of supertard in order to promote white supremacy.

NathanPhillipsAKAfmr-paultard on Sat, 16th Mar 2019 11:13 pm

I love being crazy and free to do whatever the fuck I want to do.

You know why I can do and say whatever the fuck I want? Because YOU, Mr. Taxpayer, are paying for my Social Security Disability. I get paid to be a freak. I get paid although I never paid into the system.